Electrocardiograph vs. Electrocardiogram — What's the Difference?

An electrocardiograph is a medical device designed to capture and record the electrical activity of the heart over a period of time. This device uses electrodes attached to the patient’s skin to detect the electrical changes that occur with each heartbeat. On the other hand, an electrocardiogram, often abbreviated as ECG or EKG, is the graphical output generated by an electrocardiograph. It presents the heart's electrical activity in the form of waves.

The primary function of an electrocardiograph is to monitor and measure the heart’s electrical conduction system. It translates the heart's electrical activities into line tracings on paper or screens. Whereas the electrocardiogram (ECG) serves as a diagnostic tool, enabling healthcare professionals to interpret the rhythm and functioning of the heart by analyzing the waveform patterns depicted in the output.

Electrocardiographs are complex, sophisticated machines found in hospitals and clinics, equipped with sensors and software designed to accurately capture heart activity. An electrocardiogram, however, is a relatively simple representation, consisting of lines and waves that represent the heart’s electrical activity, easily understood by trained personnel.

While the electrocardiograph requires maintenance and calibration to ensure accurate readings, the electrocardiogram itself is a consumable output, often part of a patient’s permanent medical record. The durability and operation of an electrocardiograph are critical for generating accurate electrocardiograms.

Electrocardiographs have evolved technologically, incorporating features like digital displays and connectivity for electronic health records. Conversely, the format and interpretation principles of electrocardiograms have remained consistent, focusing on the heart’s rate, rhythm, and other electrical characteristics important for diagnosis.